1. Technical Field
The present disclosure generally relates to filters, and more particularly to a band-pass filter.
2. Description of Related Art
Conventionally, when a wireless network device operates at high power, harmonic components of high frequency are generated due to the nonlinear properties of the active components of the device, causing electromagnetic interference (EMI).
To address this, a filter is often used to suppress the harmonic components. Some manufacturers use a waveguide element, such as a microstrip, formed on a printed circuit board of the device.
Features of an ideal filter are signal attenuation of zero within a pass band, becoming infinite within a stop band, and transition as sharp as possible from the pass band to the stop band, providing the shortest possible distance between a transmission zero point and the stop band. In addition, increased transmission zero points improve performance of the filter in suppression of harmonic noise. However, most filters have only one transmission zero point and are thus unable to achieve or approach these ideals.
Therefore, a need exists in the industry to overcome the described limitations.